LG KG110 - LCD Black Screen

Figure 4-18
Checking Flow
Can the PCB
board power on
normally?
No
Go to power on trouble
sector
Yes
Voltage at one
point of C324
equal to Vbat?
No
Check Vbat, and replace
C324
Yes
Voltage at pin3
of U300 is equal
to 2.8V?
No
Check R346 and re-
download software
Yes
Voltage at pin 1
of U300 is equal
to 5V?
No
Replace U300 and Check
C323 is ok?
Replace LCD module
No
Replace C323
Are R302 and
R303 ok?
Yes
No
Replace two resistors
Yes
Circuit Diagram
U300
C324
C323
R346
57
4. TROUBLE SHOOTING
4.8.2 LCD Black Screen
Figure 4-18
Checking Flow
Circuit Diagram